1. Technical Field
The present invention relates to a method and system for data processing in general, and in particular to a method and system for providing data communication between two independent buses within a data processing system. Still more particularly, the present invention relates to a method and system for controlling communication between a device on a non-proprietary bus and a device on a proprietary bus within a data processing system.
2. Description of the Prior Art
A proprietary bus is a bus that is intended for the private use of an original equipment manufacturer (OEM), and access to a proprietary bus is generally restricted in order to limit any liability from actions that may be caused by inappropriate commands being sent on the proprietary bus. One example of a proprietary bus is the Controller Area Network (CAN) bus. The CAN bus is an ISO-defined serial communications bus that was originally developed during the late 1980""s for the automotive industry. The basic design specification of the CAN bus calls for a high bit-rate, a high immunity to electrical interference, and an ability to detect any errors produced. Not surprisingly, the CAN bus rapidly came to be widely used throughout the automotive and aerospace industries over the years, mainly due to the above-mentioned advantageous features.
The CAN communications protocol, which conforms with the layered configuration defined by the Open Systems Interconnection (OSI) model, describes the method by which data are passed between devices coupled to the CAN bus. The CAN architecture defines-the lowest two layers as a data-link layer and a physical layer. The application layers are linked to the physical medium by the layers of various emerging protocols, which may be specific to a particular industry or propriety schemes defined by individual CAN users.
The present disclosure describes a method and system for controlling communication from a device on a non-proprietary bus to a device on a proprietary bus, such as a CAN bus.
In accordance with a preferred embodiment of the present invention, a gateway controller is connected between a proprietary bus and a non-proprietary bus. A message originated from a device on the non-proprietary bus intended for a device on the proprietary bus is checked by the gateway controller to determine if a transmission of the message should be permitted according to a permitted message bitmap. The permitted message bitmap contains a list of devices on the non-proprietary bus that are previously registered as able to communicate with devices on the proprietary bus and a list of permitted messages associated with each of the devices on the non-proprietary bus. The transmission of the message to the device on the proprietary bus is denied if the message is not registered within the permitted message bitmap.
All objects, features, and advantages of the present invention will become apparent in the following detailed written description.